By the time the offer for the pantyhose commercial came in, gridiron god Joe Namath was already well into an agonizing decline. Knees jellied by repeated trauma, left hamstring rolled up like a busted window shade, the iconic quarterback of the New York Jets played in just six games in 1973, a season in which he would throw for 966 total yards and a meager five touchdown passes.

Still, the Hanes hosiery brand cared little about Namath’s struggles on the field. Despite the fact “Broadway Joe” had seen his best years long ago, he was still wildly popular with the public. Women were especially taken with his sybaritic charm. More to the point, Namath’s willingness to endorse everything from La-Z-Boy recliners to Hamilton Beach popcorn poppers had made the hobbled superstar the most recognizable—and bankable—athlete of the day.

As it happens, Namath’s mangled legs were just the hook Hanes’ agency, Long Haymes Carr, needed to hoist up the moribund Beautymist line. For his part, the 30-year-old jock figured the ad would be as good for a goof as a paycheck. He had never been shy about making the occasional fashion statement, after all. Long before the NFL would joylessly ban any hint of self-expression on the part of players, Namath could be seen luxuriating on the sidelines in a full-length fur and dark glasses. While rival quarterback Johnny Unitas of the Baltimore Colts prowled the turf in a buzz cut and high-top cleats, the shaggy Namath looked something akin to an Apollo-era pimp.

It is little surprise, then, that Namath’s 30-second spot remains one of the most peculiar commercial artifacts. Clad in women’s stockings, a pair of athletic shorts and his Jets jersey, a grinning, prostrate Namath nails home the pitch. “Now, I don’t wear pantyhose,” he drawls, “but if Beautymist can make my legs look good, imagine what they’ll do for yours.” (Lest anyone wonder whether Namath was wading into David Bowie territory, the spot ends with a fetching young woman nuzzling an upright—and presumably pants-wearing—Namath.)

The ad may have helped land Namath on Nixon’s Enemies List, but Hanes couldn’t have asked for a more impactful spot.

For his part, Namath hated it. Speaking to Adweek after a recent screening of the HBO/NFL Films documentary Broadway Joe, the Hall of Famer recalled that his stomach turned the very first time he saw the ad. “I didn’t go back and look at it again for a long, long time,” he says. “But it was big.”

For marketers looking to get in bed with a high-profile sports figure, “big” is the operative term. A jock’s endorsement comes front-loaded with a wealth of desirable attributes—and risks. Still, an athlete’s ready-made fan base, established personal brand, and presumed sincerity and trustworthiness tend to outweigh any gamble in the eyes of a sponsor—and the greater those attributes, the more they will cost a marketer. For example, Chicago Bulls point guard Derrick Rose, fresh off his 2011 MVP season, is on the verge of signing a 10-year contract extension with Adidas worth a record $250 million.

Adidas is betting on Rose’s future prospects rather than his past performance. Despite becoming the youngest player in NBA history to hoist the Maurice Podoloff Trophy, Rose had a cold hand during the Bulls’ playoff run, shooting only 39 percent from the field. Chicago would fall to LeBron James and the Miami Heat in the Eastern Conference Finals, closing the books on its first 60-win season in 13 years.

But make no mistake: Rose is a star. At 23, he hasn’t quite achieved single-name zeitgeist status like Kobe or LeBron, but he puts up 25 points a game and, perhaps more importantly, moves product. Rose already outsells James in China, and his Adidas kicks are second only to Nike’s Zoom Kobe line in that market. (For Adidas, beating Kobe in China isn’t just about market share; the shoemaker still harbors a grudge against the Laker for ditching it for Nike in 2003.)

If Rose represents a reservoir of untapped potential, Tom Brady has proven his value as a pitchman for more than a decade. While not at the very top of the list of sports spokespeople (boasting an estimated $60 million in paid endorsements, PGA Tour vets Tiger Woods and Phil Mickelson are playing in a whole other league), Brady’s contracts with Movado, Glaceau Smart Water, Under Armour and Ugg bring him $10 million per year. (Contrary to what many think, Brady does not have a deal with Audi, though he did drive a loaner provided by Best Buddies International, a nonprofit that he supports. Brady made headlines in September 2010 when he crashed the $97,000 Audi S8 sedan near his home in Boston’s Back Bay neighborhood.)

Interestingly enough, for a three-time Super Bowl champion who is handsome enough to have curried favor with a Brazilian supermodel (he and Gisele Bündchen were married in 2009), Brady doesn’t do an awful lot of TV. In large part, the quarterback’s endorsements are limited to glossy magazine ads.

“I think the major difference between Tom Brady and other elite quarterbacks comes down to the sort of categories they align themselves with,” says David Schwab, managing director of Octagon First Call, which specializes in celebrity endorsements. “[Indianapolis Colts QB] Peyton Manning works with marketers who are either official NFL sponsors or spend a lot of their budgets in and around football, whereas Brady lives in a more aspirational space,” Schwab says. “Papa John’s and Gatorade just spend their money differently than Ugg and Stetson.”

TV money and a much bigger roster of brand partners give Manning the edge over Brady. Industry estimates put Manning’s annual endorsement haul at around $15 million, or a little more than twice what younger brother and New York Giants signal caller Eli Manning earns. (Eli Manning will gun it out with Brady on Super Sunday when the Giants and Patriots meet in Indianapolis for a rematch of Super Bowl XLII, which New England lost 17-14.)

According to the Davie-Brown Index, which gauges consumer perceptions of public figures, Eli has a slight edge on Brady in terms of awareness. DBI ranks the younger Manning at 79.5 (putting him up there with tough guy Chuck Norris), while Brady rates a 69.9 (on par with runt comic actor David Spade).

Should Eli Manning best Brady and the Patriots next week, he can expect to fend off a horde of marketers heretofore unsure of how to leverage his sleepy charm. (Writer David Roth may have put it best when he observed that Manning looks as though “someone just woke him up by yelling something like, ‘I think there are wolves in the house.’”)

No doubt, success irons out a whole bunch of wrinkles. “If Eli wins the Super Bowl again, I think he’ll get so many requests that he won’t possibly be able to do them all,” says Arthur Solomon, former vp, senior counselor at the PR giant Burson-Marsteller. “And there’s a danger with that. Some personalities do so many endorsements that people no longer take them seriously.”

Then, there’s Denver Broncos quarterback Tim Tebow, perhaps the most polarizing athlete of the 21st century, and so far a largely untested brand pitchman. The 6-foot-3-inch, 235-pound southpaw, who throws a football like a man falling out of a hammock, set hearts aflutter in the Mile High City when he led his 1-4 team on a phenomenal six-week run of come-from-behind victories. Tebow’s improbable run continued into the playoffs, where he steered Denver to a 29-23 sudden-death win over the defending AFC champs, the Pittsburgh Steelers. A week later, Tebow crashed back to Earth when the Pats restored order to the NFL with a 45-10 pasting of the Broncos.

The squeaky-clean Tebow has attracted more than his fair share of derision. The NFL’s answer to Ned Flanders, the fundamentalist Christian Tebow wants to save your soul, and he’s not shy about a most public display of his beliefs. His ritual of genuflecting on the field after a game inspired the “Tebowing” phenomenon, which would spread from Facebook to the opposing sideline. In the first quarter of the Oct. 29 Lions-Broncos mugging, Detroit linebacker Tim Tulloch celebrated his bone-rattling sack of Tebow by bowing in mock prayer over Tebow’s prone figure.

The venom really began spraying during the AFC Divisional playoff against New England. In the second quarter, the virulently anti-abortion, anti-gay rights group Focus on the Family aired a 30-second spot on CBS that featured young children reciting Tebow’s favorite Biblical passage. (At the University of Florida, Tebow regularly painted the legend “John 3:16” on his eye black. After doing so before the 2009 BCS title game, the verse became the highest-ranked search term, snagging over 90 million searches.)

But if Tebow’s proud professions of faith might make some twitchy, others say his overwhelming positivism is a righteous thing for marketers. “I would not have any hesitancy to recommend Tim Tebow to a client,” says Solomon. “While there may be a small percentage of people who get upset by how he may wear his religion on his sleeve, he’s a safe bet in so many ways. You won’t have to worry about him drowning a dog or getting pulled over for drunk driving or getting arrested for sexual abuse. There’s very little downside to him.” (All that presumes, of course, that Tebow is as virtuous as he appears to be.)

Schwab says that with Tebow, the greatest opportunity lies beyond NFL-facing clients. “Instead of looking at him as a way to reach that male 18-34 demo, the smart play would be to try and align him with companies that spend a lot of money via community service, outreach and mentoring,” he says. “A lot of the religious stuff seems to have been blown out of proportion by the media. Most people really respect him.”

Of course, Tebow has to prove his mettle on the field if he’s to become a $10 million pitchman. Broncos evp of football operations John Elway says Tebow has earned the starting role going into next year’s training. Still, many football analysts say the quarterback’s delivery and footwork are too wonky for the NFL and that he would be far more effective as a bruising fullback.

“The question is: Can he become an elite player?” says Schwab. “We know he could be a fantastic role model. But if he plays for a few good years and then transitions to something interesting after football, I think his fans are going to stay with him—and if that’s the case, he could have another 20 or 30 years ahead of him from a marketing perspective.”

Tebow has already secured a smattering of endorsements, including a multiyear sponsorship with Jockey International and contracts with EA Sports and Nike. All told, Tebow’s endorsements earn him an estimated $1.5 million per year.

One thing seems certain: If Tebow ends up missing out on sponsorship riches, it’ll have everything to do with his not living up to his promise and nothing to do with his gender. When it comes to sports marketing, the disparity between the earnings of male and female athletes is considerable, and in some cases shocking.

Take Team USA Soccer goalkeeper Hope Solo, who last summer helped lead the national team to the 2011 FIFA Women’s World Cup Final. (The U.S. would lose to Japan 3-1 in a penalty shootout.) Solo’s heroic turn in Germany and her subsequent appearances on ABC’s Dancing With the Stars and the cover of ESPN The Magazine’s Body Issue made the 30-year-old famous. Her Twitter feed boasts nearly 365,000 followers (up from 8,000 the day before the Japan match) while her main Facebook page has 906,000 fans.

And just how did Solo’s achievements translate to sponsorship riches? Shortly after the Cup Final, she inked a multiyear promotional deal with Gatorade believed to be worth approximately $150,000 a year. (That is not a typo.) Compare that to U.S. Men’s team scoring leader Landon Donovan’s estimated $2 million deal with the sports-drink brand.

Meanwhile, Nascar driver Danica Patrick is in rare air, banking north of $10 million a year in endorsements and joining golfer Michelle Wie and tennis stars Maria Sharapova, Serena Williams and Venus Williams as the handful of handsomely paid pitchwomen. Shortly after the racer announced she would not compete in the 2012 Indianapolis 500, opting instead for the Coca-Cola 600 in Charlotte, N.C., Patrick told Adweek that perhaps nothing earned her more attention than her long-running affiliation with GoDaddy.com.

“The fact that they air commercials in the Super Bowl is huge,” says Patrick. “It’s the one day of the year when people specifically watch TV for the commercials, so nothing matches that kind of exposure. It’s good for the brand and it helps draw attention to racing.”

The big game on Feb. 5 will mark Patrick’s tenth GoDaddy commercial since 2007. In fact, no celebrity has been featured in more Super Bowl ads than Patrick—and this year’s spot is just as cringe-worthy as all the others. It features Patrick and fitness star Jillian Michaels painting a naked model’s body with messages about the sponsor’s .co domain names. A second ad stars Patrick and the ever-tasteful Pussycat Dolls.

If GoDaddy’s in-house creative is amateurish, the company’s support of Patrick is all-pro. After a longstanding Indy Car sponsorship, GoDaddy will follow Patrick as she makes the leap to Nascar, sponsoring her at JR Motorsports at Nationwide and at Stewart-Haas Racing in the Sprint Cup Series.

While Patrick has represented a number of other brands—among them, Boost Mobile, Hot Wheels, Marquis Jet, Nationwide and Tissot—she reveals there’s one category where she hasn’t broken through. “I always wanted to get a shampoo sponsorship,” she says. “It’s hard to get them to consider someone like me because they tend to go along with the same actresses and models, but I’m trying to get them to think outside the box.”

Naturally, athletes don’t always make for the best brand ambassadors. “The risks of using an athlete as your spokesman are greater every day,” says Solomon. “Not only are they unpredictable, but the media covers these sort of transgressions in a way they didn’t 30 years ago. And with the Internet, an incident that would have blown over in a day back in the old days lives on forever.”

As Solomon points out, marketers teaming up with a retired jock or a broadcaster might be a safer play.

ESPN college basketball analyst Dick Vitale does a fair amount of endorsement work, lending his Passaic, N.J., honk and hyperactive enthusiasm to the likes of Mountain Dew, Bridgestone and Hooters. Just last week, the hoops maven was in Hartford, Conn., shooting a Diet Mountain Dew spot with fellow ESPN personalities Erin Andrews, Mike Golic and Mike Greenberg.

“I always make sure to stay with products that are first class—I’m very selective about who I represent,” says Vitale. (When reminded that Hooters might not be a mainstay of taste, Vitale demurs, saying that his spots are “clean.” And, in fact, there’s nothing in one of Vitale’s Hooters ads one wouldn’t see in the broadcast of a beach volleyball tournament.)

But as Vitale explains, there’s more to it than merely a paycheck. To date, Hooters has helped raise $2 million for the V Foundation for Cancer Research. “They’re so generous,” Vitale says before returning to the set. “A job like that is a whole different ball game.”